Bluetooth V4.1: Compatible with V4.0, V3.0, V2., 1 and V2.0 standards Chipset: CSR 8635 stereo chip Support Bluetooth function: A2DP, AVRCP, Headset Profile, Hands free Profile Transmission power: Class 2 Frequency: 2.4Ghz – 2.4835GHz, ISM Band Transmission distance: 10M Microphone sensitivity [-45dB (0dB=1V/Pa, 1KHz)] Product weight: 65g Talk time: Up to 12 hours Standby time: 250 hours Charging time: less than 8 hours Charging current: 80mA Charging voltage: 5V Working voltage: 3.3-4.2V Charger power supply: 110-240V Operation Temperature: 10 ~ 55° Rechargeable Li-Polymer battery Operating systems compatibility: Windows/MAC/Linux Software compatibility: Skype, Zoom, Microsoft Teams and other video conferencing software